Bunk for loggjng vehicles



Jan. 31, 1956 R. B. DAVIDSON 2,733,077

BUNK FOR LOGGING VEHICLES Filed Feb INVENTOR.

Roberf B. Davidson iii! United States Patent 2,733,077 BUNK FOR LOGGING VEHICLES Robert B. Davidson, Vaughn, Wash. Application February 9, 1952, Serial No. 270,863

11 Claims. c1. 2s0 -14s The present invention relates to a bunk for supporting logs on logging vehicles. It is designed primarily for use on logging trucks, although it also may be employed on other types of vehicles such as railroad cars.

It is conventional practice in logging to employ log trucks having transversely disposed bunks for supporting the logs. Each bunk is provided at each of its ends with a chock for preventing the logs from rolling oil. In additiori, there are provided one or more binder chains or cables. These are placed around the logs on the truck and the loose ends fastened together by means of a binder jack or similar mechanism. V

When the logs are to be unloaded, it is necessary to release the binder chains from a position proximate the logs. This is an extremely hazardous undertaking, since the logs may have been poorly loaded, or may have become displaced during their transportation so that they fall to the ground as soon as the chains are released. Many lives have been lost as a result of such occurrences. In addition, using such chains is a time-consuming and troublesome operation, particularly in view of the fact that they may become jammed, which necessitates cutting them, or they may become lost during the return trip of the truck.

It therefore is a primary object of this invention to "providea bunk for logging vehicles Which holds the logs securely while they are in transport, but which may be operated to release the logs from a remote station and with complete safety to the operator.

It is another object of the present invention to provide a bunk for logging vehicles which, in addition to being safe, is simple and easy to use.

It is another object of the present invention to provide abuhk for logging vehicles which holds the logs securely by means of stakes and binder cables", the stakes and binder cables being releasable simultaneously from a remote station to discharge the load.

It is another object of the present invention to provide 'a bunk for logging vehicles which is provided with stakes for retaining the load, the stakes being pivotable between raised positions wherein they retain the load, and lowered positions wherein they act as skids for discharging the load, or for loading material on the truck.

It is another'object of the present invention to provide a bunk for logging vehicles which is provided with stakes -for retaining the load, the stakes being readily removable and replaceable with chocks or short stakes when such is desired for accommodating logs of unusual dimensions. It is another object of the present invention to provide a bunk for logging vehicles which provides maximum fiat loading space for minimum vehicle width, and which will accommodate either logs or timbers of any cross-sectional dimension. 1

It is another object of the present invention to pro vide a bunk for logging vehicles which is'sturdy in construction so that it can withstand heavy blowsfrom logs being loaded thereon.

It is another object of this invention to provide a bunk 2,733,077 Patented Jan. 31, 1956 for logging vehicles which has stakes that may be maintained in a predetermined position rigidly, thereby hold ing the load securely on the vehicle in a fixed position.

I It is another object of the present invention to provide a bunk for logging vehicles which is provided with mechanism for retaining logs on the vehicleand for'discharging them therefrom, such mechanism being protected from damage without extending outwardly from the sides of the vehicle and thereby undesirably increasing its overall Width, which is limited by law.

It is another object of the present invention to provide a high stake bunk for logging vehicles, the stakes of which have smooth exterior surfaces for the logs to rub against while being loaded, thereby making possible their precise alignment with respect to the other logs comprising the load on the vehicle.

it is another object of the present invention to provide a bunk for logging vehicleswhich is provided with a binder chain or cable and means integral with the bunk for receiving and storing the chain or cable when the same is not in use, and for tightening it when it is used to restrain log loads of varying size.

It is another object of the present invention to provide a bunk for logging vehicles which is provided with both vehicle,- or to other vehicles and objects.

It is another object of the present invention to provide a bunk for logging vehicles which is particularly adaptable for use on logging vehicles of the truck-trailer type which are flexible and necessitate frequent shifting in the position of the vehicle. relative to the logs as the former turns while traversing a logging road.

It is another object of the present invention to provide a high stake bunk. for logging vehicles provided with binder cables, the cables being arranged for manual fixation after the stakes are locked in vertical position and the vehicle has been fully loaded with logs.

The manner in which the foregoing and other objects of this invention are accomplished will 'be apparent from the following specification and claims, considered together with the drawings, wherein like numerals of reference indicate like parts, and wherein: v

Figure l is a view in front elevation of the presently described bunk, partly broken away better to show the internal construction; p

Figure 2 is a plan View, partly in section, of the log truck bunk of Figurel;

Figure 3 is a detail view in side elevation of the presently described bunk;

Figure 4 is a sectional View in side elevation of the presently described bunk; and

Figure 5 is a detail sectional view taken along the lines 55 of Figure 2.

'As' is particularly apparent from Figures 1 and 2, the

frame of the log truck bunk of this invention comprises a hollow shell including the side'pieces 10, l2, which may be angle irons of substantial construction. These are interconnected at the top by a substantial top plate 14. At the.

bottom of the side pieces and substantially equidistant from their ends is a turntable cup 16 penetrated by king pin 18 bymeans of which .thebunk is rotatably mounted pair of stakes, one at each end. In general, both are of sturdy construction, having wide bases for withstanding the pressure exerted against them by the logs either when flying through the air during loading, or during transit when substantial pressures may develop. They are afiixed to the bunk frame by means of removable pins or bolts so that they may readily be replaced by chocks or short stakes where this is desired as, for example, to accommodate logs of large diameter.

Thus, stake 24 at one end of the bunk frame may be constructed with its lower portion forked, straddling the frame and bolted thereto by means of bolts 26, 28. Stake 24 may be fixed in its position relative to the bunk frame, normally at substantially a right angle thereto.

At the other end of the bunk frame is a second stake 30. Like stake 24, it is forked atits lower end and straddles the bunk frame, being held, however, by a single pivot pin 32 penetrating the stake and the bunk frame. Pin 32 is stationed at the lower outer corner of the bunk frame so that as stake 30 pivots from its log-retaining position, wherein it is substantially vertical, to its log-discharging position, where it inclines downwardly, no part of the stake base projects above the upper surface of the bunk frame. Rather, the stake base remains substantially flush with the bunk frame at all positions of the stake from its raised position to its lowered position and in all intermediate positions. As a result, no impediment is offered to logs or timbers being loaded upon or discharged from the truck.

Bolt means are provided for releasably locking the stake to the bunk frame in its log-retaining or raised position. In the illustrated embodiment the bolt means comprises a first perforated or slotted plate 34 on the top of the bunk frame beneath stake 30. Plate 34 has a slight curvature to permit easy sliding of the stake thereover. It is directly opposite a perforated or slotted plate 36 on the bottom end of stake 30, the perforations being positioned so that they are in substantial registration with each other when the stake is raised. Both of the perforations or slots preferably are tapered outwardly and downwardly.

A locking bolt 40, preferably comprising a centrally perforated plate made of strong structural steel, is mounted for vertical reciprocation in the end of the bunk from beneath stake 30. It is arranged so that as it reciprocates, it alternately enters and is withdrawn from the slots in plates 34 and 36, thereby alternately locking the stake to the bunk and releasing it. The upper end of bolt 40 preferably is hardened and tapered, the taper corresponding to the taper in theperf orations in plates 34, 36.

This construction facilitates retraction of the bolt even though it is under great pressure from the logs retained by the stakes. Also, it automatically compensates for any wear which may occur in the plates or in the bolt, thereby maintaining the stake rigidly in its predetermined position. A pair of spaced apart plates 41 welded to the underside of the bunk frame form a guide for the rear terminal portion of bolt 40 during its reciprocation.

Means are provided for operating bolt 40 at a station remote from stake 30 which, under the great pressure of the logs resting on the bunk, swings outwardly precipitously with consequent hazard to anyone standing near it. The bolt operating means comprise abell crank 42 pivotally mounted on a pin 44 attached to the bunk frame. One end 46 of the bell crank is rounded and dimensioned to enter the central perforation in bolt 40. The other end 48 is pivotally connected through pin 50 to connecting link 52 which in turn is rigidly fastened to the elongated drag link 54. The latter member of the assembly extends longitudinally Within the hollow frame of the bunk. Drag link 54 is connected to the link member 56, which in turn is connected through pivot pin 58 to a crank 60. Crank 60 in turn is pivotally mounted onpivot pin 62 which is cut away and mounted by means of pin clamp 64 on angle iron 12 in the manner indicated particularly in Figure 5.

Crank 60 is bolted to operating lever which, like drag link 54, extends longitudinally of the bunk frame but exteriorly thereof. It extends to the side of the frame remote from stake 30, where it is held in place by means of the recessed stop member 72. Attached to its outer end is a rope 73.

It will be apparent that when lever 70 is moved in a clockwise direction, as viewed in Figure 2, by pulling on rope 73, the end 46 of bell crank 42 will operate in the central perforation in bolt 40 to withdraw the same from the perforation in plate 36 on stake 30. The latter stake then will be urged outwardly by the pressure of the logs, pivoting to its log-discharging position about pin 32.

Flexible log binding means are provided to assist in retaining the logs on the bunk. Such means are coordimated with the pivotally mounted stake 30, and in the illustrated embodiment comprise a cable 74 having at one of its ends a plurality of chain links 76. Cable 74 is fastened at the end opposite the chain links to .winch means for storing it and for adjusting its effective lengtlnand tension to accommodate a load of any given dimension.

The winch preferably is built within fixed stake 24 and comprises the reel 77 journaled between side plates 10, 12 of the bunk frame and having an extension penetrating the face of stake 24 adjacent lever 70. On this extension is a ratchet 78 operated by means of a pawl 80 on operating lever 82. Lever 82 preferably is removably contained in a sheath 84 which is pivotally mounted on the extension of the shaft of reel 77. As a result, the reel may be located close to the outer edge of the vehicle to preserve the effective width of the bunk, but without including a lever arm which extends beyond the side of the truck and which consequently is subject to damage, and might violate local laws governing the width of log trucks.

It will be apparent that rotation of ratchet 78, in a counterclockwise direction, as viewed in Figure 1, will wind cable 74 on the reel, thereby tightening it. When so tightened, it may be maintained taut by means of the finger 86 positioned for engaging ratchet 78 and restraining it against the pull of the cable. A crank (not illustrated) may be provided for engagement with angular section 88 of the reel shaft for operating the reel upon disengaging pawl 80 and finger 86, as would be desirable, for example, when reeling in a substantial portion of cable 74 for storing the same when no logs are on the truck.

Cable 74 is guided through an opening in the top of stake 24 by means of the fixed spool or guide 90 spaced apart from bolt 92. Chain 76 at the end of the cable is guided similarly through an opening in the top of stake 30 formed by a spool 94 spaced apart from bolt 96. This construction prevents logs loaded above the level of the stakes from working their way outside the stakes and thereby damaging the bunk and making their release hazardous.

Latch means are provided for releasably lockingbinder chain 76 to stake 30. In its illustrated embodiment, the latch means comprises (Figure 4) a locking bar which is slidably mounted lengthwise of stake 30 in engagement with the outer face of the latter, being retained between the spaced latch block 102 and guide plate 104, both of which are secured, as by welding, to the outer face plate of stake 30. The locking bar is retained against the face plate by the transverse bolt 106 mounted in the side plates of stake 30. A projection 108 is provided on the outer face of locking bar 100. It extends outwardly through an opening 109 in the outside face oflstake 30, whereby the bar may be reciprocated man ua ly.

A latch member 110 is positioned below latch block 102 and is slidably mounted longitudinally of the stake, being retained byguide plates 112, 114 and the transverse bolts 116, 118. As shownin, Figure ,4, the latchmemher 110 is notched at its upper end to receive the lower end of locking bar 100. An opening 119 i n the face of stake 30 is provided directly opposite the meeting point eraser? of latch block 102 and latch member 110. It will be apparent that upon lifting locking barl00, links of chain 76 may be inserted through opening 119 and one of the links may he slipped horizontally between the adjacent edges of latch block 102 and latch member 110. Then by lowering the locking bar 100 the chain link will be locked securely in place Without any possibility of its slipping sideways or being withdrawn even When great stresses are placed upon it by the logs it contains.

To facilitate release of the chain from the latch means when this is desired, the inside edges of the opposed ends of latch block 102 and latch member 116 may be beveled or rounded sufficiently so that as tension is placed on the chain there is a slight resultant tendency to separate the latch block 102 and latch member 110. This overcomes any frictional locking tendency which might prevent the release of the chain upon opening of the latch.

Latch member 110 is coordinated with bolt 49 and operable by the same. It rests on an adjusting screw 120 by means of which the space between it and latch block 102 may be adjusted to a predetermined value. Screw 120 in turn is attached to one end of a rocker arm 122, which is pivotally attached to stake 3%) by means of pivot pin 124. On the underside of rocker arm 122 is a pro jection 126 which is in direct contact with the upper edge of bolt 40, serving as a wear member and follower for the bolt.

Tensioning means are provided for normally urging latch member 110 into its retracted position with respect to latch block 102 Such means may comprise, for example, a spring 128 interconnecting latch member 110 and the stake frame. It will, be noted that when bolt 40 is advanced, penetrating the perforation in stake plate 36 and locking stake 30 in its log-retaining position, the opening between latch block 102 and latch momher 110 will be substantially closed so that a chain contained between these two members will be gripped thereby and firmly held in place. Then as bolt 40 is withdrawn from plate 36, 'the latch will be opened and the stake released. However, because of the amplifying action of rocker arm 122, the latch will open prior to the release of the stake. This is desirable since it permits release of the chain by a comfortable margin before the stake is released and forced outwardly and downwardly by the pressure of the logs behind it. This prevents breaking of cable 74 or chain 76 when the logs fall from the truck.

Operation In operation, when logs are to be loaded on the truck, stake 30 and its counterpart on any of a plurality of bunks with which the truck may be provided, is adjusted to its raised position with bolt 40 penetrating plates '34 and 36 and with latch member 110 in its elevated position. Chain 76, together with cable 74, is removed from the top of the truck. 7

Logs then are stacked on the bunks in the usual manner. This involves lifting the logs and swinging them over to the truck where they are aligned by resting them momentarily against the stakes. Such a manner of loading obviously makes it imperative that the stakes be rigid and strong. They also must present a smooth exterior surface so that one end of the log will not snag and be retarded while the other end swings crosswise of the load. They then are slid rapidly up the side of the stake and dropped inside before they swing across the load.

Next, cable 74 is thrown over the top of the load and drawn manually as tight as possible. Lockingbar 100 is lifted by means of projection 108, and chain 76 inserted between latch block 102 and latch member 110.

held securely in place. ened by operation of the winch including ratchet 78 operated by the removable handle 82.

The load is transported to its unloading point which may be, for example, a log dump where the truck is driven alongside a brow log below which are skids or a chute leading to the log pond. The operator then releases lever from guide 72 and standing at a remote station, jerks rope 73 on the end of the lever. one bunk at a time may thus be tripped, or all operated simultaneously, as the load condition indicates.

Moving lever 70 by jerking the rope will move crank 42 in a counterclockwise direction, as viewed in Figure l, withdrawing bolt 40 from the slot in plate 36. Such withdrawal first permits latch member 119, urged by spring 128, to draw apart from latch block 102, releas ing chain 76. After the chain has been released, stake 3t) falls outwardly and downwardly against the brow log where it acts as a skid, over which the logs tumble on their way to the pond. Chain 76 runs freely between spool 94 and bolt 96 during this operation.

After the logs have been unloaded, cable 74 maybe wound on reel 76, and stake 30 returned manually to its raised position. There it is locked in place by a suitable if, as sometimes occurs, the logs are dumped over the side of a precipitous incline which is inaccessible, it may be difiicult, if not impossible, to elevate stake 30 manually. In such a case, chain 76 may be connected to the stake and the latter raised by operation of the winch. It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of my invention, or the scope of the subjoined claims.

Having now described my invention, I claim:

1. A bunk for logging vehicles comprising a bunk frame, a slotted plate on the terminal portion of the frame, a stake, means for pivotally attaching the stake to said terminal portion of the frame for permitting the outward angular movement of the stake relative to the,

vehicle, a slotted plate on the end of the stake adjacent the bunk frame, the slots in the frame and the plateregistering when the stake is in its log-retaining position on the bunk, a recessed blade extendable into the slots when they are in registry, thereby releasably locking the stake in its log-retaining position, a bell crank pivotally attached to the bunk frame with one of its ends extending into the recess in the blade and in sliding contact therewith, and lever means attached to the other end of the bell crank for reciprocating the blade from a station remote from the stake.

2. A bunk for logging vehicles comprising a bunk frame, a slotted plate on' the terminal portion of the frame, a stake, means for pivotally attaching the stake to said terminal portion of the frame, a slotted plate on 'the end of the stake adjacent the bunk frame, the slots in the frame and the plate registering when the stake is in its log-retaining position on the bunk, a blade extendable into the slots when they are in registry, thereby releasably locking the stake in its log-retaining position,

the blade having an opening transversely therethrough, a first bell crank pivotally attached to the bunkframe with one of its ends extending into the opening in the blade in sliding contact therewith, a link member attached to the other end of the first bell crank and extending parallel to the bunk frame, a second bell crank pivotally mounted centrally of the bunk frame and connected to the link member, and a lever attached to the second bell crank and extending parallel to the bunk frame substantially to the end thereof opposite the end at which the said stake is mounted, thereby enabling operation of the blade for locking and tripping the stake at a station removed from the same.

3. A bunk for logging vehicles comprising a bunk frame, a stake, means for pivotally mounting the stake at an end of the bunk frame for oscillation between a raised logmanipulation of lever 70, which then is placed in stop retaining position and a lowered log-discharging position, bolt means releasably interengaging the frame and the stake for releasably maintaining the stake in the raised log-retaining position, flexible log binding means, means for fastening one end of the log binding means on the side of the vehicle opposite the stake, and latch means in the stake for engaging the other end of the log binding means, the latch means being positioned for actuation by the bolt means for releasing the log binding means jointly with release of the stake.

4. A bunk for logging vehicles comprising a bunk frame, a stake, means for pivotally mounting the stake at an end of the bunk frame for oscillation between a raised log-retaining position and a lowered logdischarging position, bolt means releasably interengaging the frame and the stake for releasably maintaining the stake in the raised log-retaining position, flexible log binding means fastened at one of its ends on the side of the vehicle opposite the stake and adapted to pass over a load of logs on the vehicle for binding the same thereon, guide means for guiding the log binding means through the top of the stake, and latch means on the stake for releasably securing the other end of the log binding means thereto, the latch means being positioned for actuation by the bolt means, thereby securing disengagement of the latch means jointly with the release of the bolt means.

5. A bunk for logging vehicles comprising a bunk frame, a stake, means for pivotally mounting the stake at an end of the bunk frame for oscillation between a raised log-retaining position and a lowered log-discharging position, bolt means releasably interengaging the frame and the stake for releasably maintaining the stake in the raised log-retaining position, flexible log binding means fastened at one of its ends on the side of the vehicle opposite the stake and adapted to pass over the top of logs on the vehicle for binding the same thereon, a pair of latch members spaced from each other and one being mounted for reciprocation toward and away from the other, thereby providing a closable opening for receiving and retaining the other end of said log binding means, and means for connecting the said one of said latch plates to the bolt means, whereby to open the latch and release the log binding means jointly with release of the stake by the bolt means.

6. A bunk for logging vehicles comprising a bunk frame, a stake, means for pivotally mounting the stake at an end of the bunk frame for oscillation between a raised log-retaining position and a lowered log-discharging position, bolt means releasably interengaging the frame and the stake for releasably maintaining the stake in the raised log-retaining position, flexible log binding means fastened at one of its ends on the side of the vehicle opposite the stake and adapted to pass over logs on the vehicle for binding the same thereon, an upper latch member on the stake, a lower latch member on the stake spaced apart from the upper latch member and mounted for vertical reciprocation with respect thereto, thereby forming a closable opening for receiving the other end of the log binding means, and a rocker arm pivotally mounted on the stake below the lower latch member, the rocker arm being positioned for contact by the bolt means, thereby enabling separation of the latch members jointly with disengagement of the bolt means from the stake.

7. A bunk for logging vehicles comprising a bunk frame, a stake, means for pivotally mounting the stake at an end of the bunk frame for oscillation between a raised log-retaining position and a lowered log-discharging position, bolt means releasably interengaging the frame and the stake for releasably maintaining the stake in the raised log-retaining position, flexible log binding means fastened at one of its ends on the side of the vehicle opposite the stake and adapted to pass over logs on the vehicle for binding the same thereon, an upper latch member on the stake, a lower latch member on the stake spaced apart from the upper latch member and mounted for vertical reciprocation with respect thereto, thereby forming a closable opening for receiving the other end of the log binding means, a rocker arm pivotally mounted on the stake below the lower latch member, and an adjusting screw interposed between the rocker arm and the lower latch member for adjusting the position thereof relative to the upper latch member and thereby fixing at a predetermined value the dimension of the opening between the two latch members, the rocker arm being positioned for contact by the bolt means, thereby enabling separation of the latch members jointly with disengagement of the bolt means from the stake.

8. A bunk for logging vehicles comprising a bunk frame, a stake, means for pivotally mounting the stake at an end of the bunk frame for oscillation between a raised log-retaining position and a lowered log-discharging position, bolt means releasably interengaging the frame and the stake for releasably maintaining the stake in the raised log-retaining position, flexible log binding means fastened at one of its ends on the side of the vehicle opposite the stake and adapted to pass over logs on the vehicle for binding the same thereon, an upper latch member on the stake, a lower latch member on the stake spaced apart from the upper latch member and mounted for vertical reciprocation with respect thereto, thereby forming a closable opening for receiving the other end of the log binding means, a rocker arm pivotally mounted on the stake below the lower latch member, and tensioning means connected to the lower latch member for urging the same normally to its open position, the rocker arm being positioned for contact by the bolt means, thereby enabling separation of the latch members jointly with disengagement of the bolt means from the stake.

9. A bunk for logging vehicles comprising a bunk frame, a stake, means for pivotally mounting the stake at an end of the bunk frame for oscillation between a raised log-retaining position and a lowered log-discharging position, bolt means releasably interengaging the frame and the stake for releasably maintaining the stake in its raised log-retaining position, flexible log binding means fastened at one of its ends on the side of the vehicle opposite the stake and adapted to pass over logs on the vehicle for binding the same thereon, a latch block mounted on the stake, and a latch member reciprocably mounted on the stake opposite the latch block for engaging the free end of the log binding means, the latch member being positioned for opening by the bolt means, thereby releasing the log binding means jointly with release of the bolt means.

10. A bunk for logging vehicles comprising a bunk frame, a stake, means for pivotally mounting the stake at an end of the bunk frame for oscillation between a raised log-retaining position and a lowered log-discharging position, bolt means releasably interengaging the frame and the stake for releasably maintaining the stake in the raised log-retaining position, flexible log binding means fastened at one of its ends on the side of the vehicle opposite the stake and adapted to pass over logs on the vehicle for binding the same thereon, winch means on the end of the frame opposite the stake, flexible log binding means attached at one of its ends to the winch means, latch means on the stake for releasably receiving the other end of the log binding means, and means for interconnecting the latch means and the bolt means for opening the latch means and releasing the log binding means jointly with release of the bolt means and pivoting of the stake from its log-retaining position to its log-discharging position.

11. A bunk for logging vehicles comprising a bunk frame, a stake, means for pivotally mounting the stake at an end of the bunk frame for oscillation between a raised log-retaining position and a lowered log-discharging position, bolt means releasably interengaging the frame and the stake for releasably maintaining the stake in the raised log-retaining position, flexible log binding 2,733,077 9 10 means fastened at one of its ends on the side of the vehicle for actuation by the bolt means, thereby opening the opposite the stake and adapted to pass over the top of a latch and releasing the log binding means jointly with load of logs on the vehicle for binding the same thereon, a diseflgagfiment 0f e bolt and rel se of the first stake. second stake attached to the end of the frame opposite the first stake, winch means mounted adjacent the sec- 5 References Cited In the file of this Patent ond stake, flexible log binding means connected at one UNITE S TE T NT of its ends to the winch means for varying the effective 969,218 stie h i Sept, 6, 1910 length of the log binding means, and latc'h means on 1,454,037 Byrne May, 8, 1923 the first stake for releasably engaging the other end of 10 2,256,623 Newman, Sr. Sept. 23, 1941 the log binding means, the latch means being positioned 2,565,748 Van Vleet Aug. 28, 1951 

